Fat stores estrogen.  It also creates estrogen.  That's why fat men take on such a feminine look and why fat women have a higher incidence of breast cancer.

In the twenty years I've been on hormones, I've had occassion to be on a diet more than once.  I've discovered a few things that might be of interest.

When I diet, the fat dissolves and releases extra estrogen into my system.  As we all know, estrogen has both physical and mental/emotional effects.  Though I keep my hormone doses steady, the extra estrogen  causes such physical effects as tender breasts and water retention, and such mental/emotional effects as become a little less focused and an increased sense of general well being.  This is also accompanied by  a more feminine sense of self in an emotional context.

In fact, if I want to stay in a more logical state of mind, I have to lower my hormone regimine to compensate for the extra levels from the fat.  Or, I can just keep the levels steady and ride the high.

If you are on high enough doses of estrogen as a regular regimine, you may not notice any difference when losing weight.  But for me, at age 56, I try to keep my dosages at the minimum level necessary to keep the positive physical effects going and maintain a healthy mental balance.  So, I use the "estrogen boost" as a reward for a good day's dieting.  If I get hungry enough between meals, fat dissolves, I feel great, and it encourages me to keep losing weight.